FR2542055A1 - GEAR SYSTEM - Google Patents

Abstract

THE SYSTEM INCLUDES TWO CROWNS DIRECTLY IN ENGAGED WITH A COUPLING RING RATHER THAN BEING THROUGH A COUPLING RING. IN THE EXAMPLE DESCRIBED, TWO CROWNS 46, 48, MOUNTED SIDE BY SIDE ON A SAME AXLE 49, HAVE HELICOIDAL BEARING TEETHES 60, 62 IN ENGAGED WITH HELICOIDAL TEETH 66, 68 OF REVERSE TILTS OF SATELLITES 64 ENGAGING WITH A PLANETARY 72. THE CROWNS 46, 48 HAVE STRAIGHT OUTER COUPLING TEETH 56, 58 OFFSET EQUALLY TO ONE ANOTHER FROM THE CENTERS OF THE BEARING TEETH 60, 62. THESE STRAIGHT TEETH 56, 58 ENGAGE WITH A RIGHT INTERNAL COUPLING TEETH OF AN ANNULAR BODY 40. THE CROWNS 46, 48 HAVE MUTUALLY OPPOSED STOPPING MEANS, WITH LUBRICATED SURFACES 74, 76, TO ALLOW RESPECTIVE TRANSVERSAL FORCES ACTUALLY ENGINEERED BY THE CENTER AXIS AND AUDITED FORCES ACTUALLY ENGAGED BY THE CENTERS. TO BE OPPOSED BY RESPECTIVE REACTIONS, ACTING IN OPPOSITION, EXERCISED BY THE CROWNS 46, 48 AGAINST THE OTHER.

Description

GEAR SYSTEM

  The invention relates to a gear system.

  A well-known form of gear system includes

  toothed wheels each having two external helical teeth

  the inverted inclinations meshing with internal teeth

  rolling helicoidals, inverted inclinations as well, of two

  These latter also include external teeth.

  helicordal coupling heads by virtue of which the rings are connected to a common coupling member provided with helical inner teeth for coupling of inverted inclinations. This common member is furthermore provided with a right external coupling toothing by which it is connected. connected to an outer member provided

  a right internal coupling toothing.

  A misalignment between, on the one hand, the axis of rotation of the outer coupling member and, on the other hand, the common axis of rotation of the rings and the inner coupling member is compensated by relative longitudinal sliding between the two teeth

mating rights.

  The object of the invention is to eliminate the coupling member

TER AL.

  According to the invention this object is achieved by a gear system

  comprising toothed wheels each having two external teeth

  helicoi 7 dales of inverted inclinations respectively meshing respectively

  with two helical inner helical bearing teeth-

  of the same diameter mounted side by side on the same axis and an annular coupling member having an internal toothing

  right of coupling and which is arranged concentrically to the

  to which it is coupled, characterized in that the crowns

  each have a right external coupling toggle in engagement with the right internal toothing of said member, the outer outer teeth of coupling of the crowns being shifted towards one another from the centers of the rolling teeth of the respective crowns and the latter having mutually opposite abutment means 2 -

  lubricated surfaces so that transverse forces remain

  objectives actually created for those centers and acting in parallel

  such common axis are countered by

  pectives acting in opposition and exercised by the crowns relying on each other. Advantageously, the coupling teeth of the crowns are shifted towards one another by an equal distance from the centers of the

  bearing teeth of the respective crowns.

  Advantageously, the mutually opposite abutment means are formed by the two sets of lateral faces which the

  mating teeth of the respective crowns.

  Advantageously also, the means of abutment mutually oppo-

contact each other directly.

  The invention is applicable to epicyclic gear systems.

  and other gear systems of similar types

  the epicyclic gear systems to which the invention applies

  The following four types of systems can be mentioned: firstly, a fixed outer ring gear with a planetary gear connected to a high speed shaft, a planet carrier connected to a low speed shaft, and the shafts rotating in the same direction; secondly, a system

  fixed planet carrier with planetary gear connected to a high speed shaft,

  an outer ring connected to a low speed tree, and

  in opposite directions; thirdly, a fixed planetary system with an outer ring connected to a high-speed shaft, a planet carrier connected to a low speed shaft, and the trees rotating in the same direction; and fourthly, a so-called differential system, with a crown,

  planetary and with all three rotating planet carriers.

  In the accompanying drawings, given by way of example, FIG. 1 is a diagrammatic view in longitudinal section of a part of an epicycloidal gear system of known type; Figure 2 is a section illustrating the consequences of the reversal effect obtained with the system shown in Figure 1; Figure 3 is a schematic sectional view similar to that of Figure 1 illustrating a portion of a system according to the invention; and

  Figure 4 is a section illustrating how the reversal effect

  can be countered by the system shown in Figure 3.

  The system partially shown in FIGS. 1 and 2 is a well-known epicyclofdal gear system Allen-Stoeckicht. This system comprises a coupling sleeve 10 which, in a gear system of the second type mentioned above, is connected by via a part 12 to a low speed shaft (not shown)

  of the system The sleeve 10 has a right internal toothing of

  coupling (not shown) meshing with a right external coupling toothing 14 of an inner coupling ring 16 La

  ring 16 has two internal helical coupling teeth.

  inverted inclination dales (not shown) near its ends. The system further comprises two like toothed rings 18 and 20 mounted next to each other on a common axis and provided with

  external helical gear teeth 22 and 24, respec-

  Finally, meshing with the coupling teeth of the ring 16.

  The toothed rings 18 and 20 are further provided with teeth

  helical rolling bearings with inverted tilts 26

  and 28 satellites (not shown) each having two teeth

  helical bearings of inverted inclinations, are mounted on journals in bearings carried by a planet carrier (no -4

  shown) within the toothed rings 18 and 20 and their teeth

  res mesh with the teeth of the latter, respectively.

  A central or planetary wheel (not shown) meshes with

  satellites in a well-known way.

  When the system operates, forces are generated at the helical bearing teeth of the rings 18 and 20, which act tangentially, radially and transversely (i.e.

  parallel to the axis of rotation of the crowns).

  Slight misalignment between, on the one hand, the axis of rotation

  of the member 10 and, on the other hand, the common axis of rotation of the member 16.

  and toothed rings 18 and 20 are compensated by a long sliding

  the relative velocity of the toothing 14 and the toothing with which it is

in take.

  FIG. 2 illustrates transverse forces T generated at the centers 30 and 32 of the rolling teeth -26 and 28 of the rings 18 and 20,

  opposing T (K) reactions due to the coupling teeth

  of the coupling ring 16, these reactions acting on the centers 34 and 36 of the coupling teeth 22 and 24 of the rings 18 and 20, respectively The centers 34 and 36 of the coupling teeth 22 and 24 are shifted towards the outside relative to the centers 30 and 32 of the coupling teeth 26 and 28 so that it exerts a couple of

  torsion on each of the rings 18 and 20, producing the distortion

  presented, that is a swelling of the inner edges, called the effect of

  tournement. FIG. 3 shows a gear system of the second type

  in which the inner coupling ring 16 represents

in Figure 1 is deleted.

  The system comprises a coupling sleeve 40 connected by

  via a piece 42 to a low speed shaft 44 of the system.

  The sleeve 40 has a right internal coupling toothing

  (not shown) meshing with straight outer teeth of

  coupling 56 and 58, respectively arranged on extensions

  52 and 54 of toothed crowns 46 and 48.

  The crowns 46 and 48 are mounted in a juxtaposed manner on a

  common axis 49 and have respectively coupling teeth

  internal helical 60 and 62 inverted tilts.

  Dez satellites 64, each having two helical bearing teeth 66 and 68 of inverted inclinations, are mounted on pins carried by a planet carrier 70, inside the crowns

  teeth 46 and 48, and their teeth 66 and 68 are in contact with the teeth.

  60 and 62 of the crowns 46 and 48, respectively The satellite holder

  lites 70 is connected to a member 71 for torque reaction: a central wheel

  the or sun gear 72 meshes with the satellites 64 in a well known manner.

  The extensions 52 and 54 of the toothed crowns 46 and 48 extend

  tooth towards each other, the straight coupling teeth 56 and 58 being juxtaposed The adjacent lateral surfaces 74 and 76 of the teeth 56

and 58 are contacting each other.

  Figure 4 shows the ring gear 48 in more detail.

  The other ring gear, 46, is similar.

  The effective centers of the rolling teeth 62 of the crown 48

  The transverse forces T and radial R are

  felt as acting on a tooth 62.

  The lateral faces 76 of the teeth 58, which contact the lateral faces

  74 teeth 56 of the ring 46, together form means

  stop, the lateral faces 74 of the teeth 56 forming means for

for the crown 46.

  The transverse forces T at the teeth 58 of the crown 48 oppose the reaction forces T (R) produced by the ring 46 and

  which act parallel to the forces T on the stop means 76.

  The latter are, in the radial direction, offset from the centers 78 by a distance D1 so that it exerts a torque of torsion dextrorsum

TD 1 on crown 48.

  Radial forces R at the level of the teeth 62 are opposed by

  these reaction that produces the coupling sleeve 40 and which act

on the flanks of the teeth 58.

  In reality, the forces at the coupling teeth are divided into several teeth. For the sake of clarity, the transverse and radial forces are represented as acting in the same plane as

  the forces acting on the rolling teeth.

  The radial component R (R) of the reaction forces at the coupling teeth 58 is shifted from the centers 78 of the teeth 62, in axial direction, to the other ring 46 so that it is exerted on the

  crown 48 a torsion torque senestrorsum.

  Since torques are in opposite directions, they occur

  gives a deformation of the crown 48 much less and even zero

in some cases.

  The magnitude of the transverse forces T equals the magnitude of the

  reaction forces T (R) and is given by the product of the tangential force

  of the tooth 56 or 58 and the tangent of the angle of

Tooth tooth.

  The magnitude of the radial force R is given by the product of the tangential force acting on tooth 60 or 62 and the tangent of

  the pressure angle for tooth 60 or 62.

  The magnitude of the reaction R (R) is not equal to that of the

  This R is given by the product of: (i) the tangential force exerts

  on tooth 60 or 62, (ii) the tangent of the pressure angle at

  calf of mating tooth 56 or 58; (iii) the quotient of rn over r 2,

  o rl is the radius of the rolling toothing 62 (or 60) up to the cen-

  very 78 of his teeth and r 2 is the radius of the coupling 58

  (or 56) to the actual centers of his teeth.

  The torque of torsion senestrorsum has a value R (R) D 2 + RD 3, where D 2 and D 3 are the distances between the lines of action of the force of

  reaction R (R) and the radial force R, respectively, from the center

  gravity section 80 of the crown section shown in FIG. 4.

  Thus, although it is possible for opposite torsion pairs to be equal, they will not be equal in general because the dimensions of

  crowns are in the first place determined by all other factors.

  Angular misalignment between the axis of rotation of the

  40 and the common axis of rotation of the toothed crowns 46 and 48 are

254205 S

  compensated by a relative longitudinal sliding between the teeth

  coupling lines 56 and 58 and the inner right teeth with la-

  which they mesh in the organ 40.

  In Figures 1 and 3, the teeth 14, 22, 24, 56 and 58 are

  The rings 84 within the body 10 or 40 in each case are held in place by elastic retaining rings 84.

  can slide more or less parallel to the axis of rotation of the

  10 or 40 to allow articulation movement between the

  ganes 10 and 16 or between the member 40 and the crowns 46 and 48 caused

  by the angular misalignments mentioned above.

  One of the lateral faces of the ring 46 is hollowed out at 86, up to the root of the teeth 56, to allow the lubricant to be

  brought to the surfaces in contact with the teeth 56 and 58. The lubricant is, however,

  supplied to the rolling teeth 60 and 62 and the trunnions of the

  lites and it is the centrifugal force that forces it to flow into the

  this cut between the crowns 46 and 48.

  In some variants not shown, the recess does not extend to the root of the teeth, or there is no recess at all, in which case radial grooves or other means of irrigation are provided for bring lubricant to cross the lateral face of the crown to end in the teeth or to bring lubricant to the side surfaces in contact with the crowns In some cases it

  There is no contact between the lateral surfaces of the teeth, but only

  between lateral surfaces elsewhere on the crowns.

  The two crowns may where appropriate both have recesses in their opposite faces and may optionally be

  identical, one of the crowns, however, being the inverted image of the

be.

  In another variant not shown, the coupling teeth

  56 and 58 do not occupy a median position in relation to the

  total axial value of the two rings 46 and 48, measured together.

  Instead, the coupling teeth 56 and 58 are, in this case,

  offset from the middle of the assembly formed by the rings 46 and 48.

  2 t 542055 In some applications not shown, the rings 46 and 48 may have different axial lengths, in which case the shifts of the coupling teeth 56 and 58 from the middle of the

  respective sets of crowns do not need to be equal.

  In yet another variant not shown, the opposite stop means that the rings 46 and 48 contact intermediate annular means disposed between the crowns instead

  to contact each other directly, lubricant being supplied to all sur-

faces in contact.

  In the system described above in connection with FIGS. 3 and 4, the reversal effect is countered only in one direction of transmission.

of torque by the system.

  In yet another variant, not shown, the member 40 is connected to another member of the system by a coupling gear to the

place of bolts.

-9

Claims (4)

  1 gear system comprising gear wheels (64) having   each of two helical outer teeth (66, 68) inclined   inverted sounds meshing respectively with the helical internal race teeth (60, 62) of two rings (46, 48) of the same diameter mounted next to each other on the same axis (49) and an annular member of coupling (40) having an internal toothing   right of coupling and which is arranged concentrically to the   (46, 48) to which it is coupled, characterized in that the   (46,48) each have a right external toothing of ac-   coupling (56, 58) engaged with the inner toothing of said or-   (40), the right outer coupling teeth (56,58) of the crowns (46,48) being offset towards each other from the centers (78) of the tread (60, 62) of the crowns respective ones (46, 48) and the latter having mutually opposite abutment means with lubricated surfaces (74, 76) so that transverse forces   actually generated at those centers and acting in parallel   parallel to said common axis (49) are counteracted by respective reaction forces acting in opposition and exerted by the rings (46, 48). leaning on each other.   System according to Claim 1, characterized in that the   of the coupling (56,58) of the crowns (46,48) are shifted towards each other by an equal distance from the centers (78) of the teeth of   bearing (60,62) respective crowns (46,48).   System according to one of the preceding claims,   characterized in that the mutually opposing abutment means (74, 76) are formed by the two sets of side faces (74, 76) of the mating teeth (56, 58) of the respective crowns (46,48).   System according to one of the preceding claims,   characterized in that the mutually opposed abutment means (74, 76) contact each other directly.